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To: dayglored
“ It's known natural orbital change (it drifts away from Earth a couple inches per year)”

What causes this?

19 posted on 05/29/2026 8:16:29 AM PDT by circlecity
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To: circlecity

Celestial mechanics...don’t ask me more than that lol


22 posted on 05/29/2026 8:29:22 AM PDT by citizen (All Bush-era RINOs have got to be primaried out.)
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To: circlecity; citizen
>> What causes [the Moon to drift away from the Earth]?

> Celestial mechanics...don’t ask me more than that lol

The primary factor is the oceans on Earth. The Moon (and to a lesser degree the Sun) pulls the ocean water into what we call "tides". Similarly, the tidal "bulges" pull the Moon, and due to the friction of the water moving on the Earth surface, as the Earth rotates (much faster than the Moon revolves around the Earth), the bulges lead the Moon and actually speed it up a little bit.

Speeding up a satellite (like the Moon) does affect its orbit, specifically it raises the orbital altitude, thus the Moon moves farther from the Earth. It's only an inch and a half per year, but it means in about 600 million years the Moon will no longer completely cover the Sun during a Solar eclipse, so no more total eclipses.

But also, the same friction of the oceans is slowing Earth's rotation (that's where the energy to speed up the Moon comes from), and in around 200 million years, an Earth day will be 25 hours long, and eventually (billions of years, assuming the Sun doesn't give up first), Earth and Moon will become tidally locked at the same rotational rate, meaning the Moon will stand still in the sky.

Don't hold your breath. :-)

32 posted on 05/29/2026 8:52:41 AM PDT by dayglored (This is the day which the LORD hath made; we will rejoice and be glad in it. Psalms 118:24)
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To: circlecity; dayglored

Climate Change.............


41 posted on 05/29/2026 9:13:15 AM PDT by Red Badger (Iryna Zarutska, May 22, 2002 Kyiv, Ukraine – August 22, 2025 Charlotte, North Carolina Say her name)
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